RadhaKrishnan wrote:
A car traveling at a certain constant speed takes 2 seconds longer to travel 1 kilometer than it would take to travel 1 kilometer at 75 kilometers per hour. At what speed, in kilometers per hour, is the car traveling?
A. 71.5
B. 72
C. 72.5
D. 73
E. 73.5
Extra time taken = 2 sec = 2/3600 hour = 1/1800 hour
Time taken to travel 1 km at 75 km/hr = 1/75 hour
Time taken for car = 1/75 +1/1800 = (24 + 1)/1800 = 25/1800 = 1/72 hour
Speed = distance/time = 1/(1/72) = 72 km/hr
Answer choice B
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